Patent GB-932011-A (GB)
Title: Improvements in or relating to dithiophosphonic acid ester derivatives suitable for use as insecticides
IPC: C07F9/165
Filed: 1959-07-13
Abstract: O,O-dialkyl dithiophosphoryl fatty acid amides of the general formula: <FORM:0932011/IV(a)/1> wherein R1 and R2 which may be the same or different are straight or branched chain alkyl groups containing from 1 to 4 carbon atoms, R3 is hydrogen, a straight or branched chain alkyl group containing from 1 to 3 carbon atoms or a phenyl radical which may be either unsubstituted or bear one or more halogen substituents and/or C1-C3 alkyl groups and/or nitro groups and R4 and R5 which may be the same or different are hydrogen or alkyl, cycloalkyl, hydroxyalkyl, hydroxychloroalkyl, or aryl groups, said aryl groups being either unsubstituted or being substituted by one or more halogen substituents and/or C1-C3 alkyl groups and/or nitro substituents or R4 and R5 together with the N atom to which they are attached form a heterocyclic ring, e.g. ethyleneimino, piperazino, pyrrolidino, piperidino or morpholino, are obtained by reacting a neutral salt of a O,O-dialkyl dithiophosphoryl fatty acid of the general formula: <FORM:0932011/IV(a)/2> wherein R1, R2 and R3 are as defined above and A is a salt-forming monovalent cation, e.g. sodium, potassium or triethylammonium, with an acid chloride XCl wherein X is an acyl radical derived from a carboxylic acid so as to yield a mixed anhydride of the formula: <FORM:0932011/IV(a)/3> and reacting the latter with an amine of the formula HN(R4)(R5) wherein R4 and R5 are as defined above to form the desired amide product. Both stages of the reaction proceed most advantageously at between -10 and +25% C. and are preferably carried out in an inert organic solvent, e.g. a hydrocarbon, high boiling point ether, or ketone. The mixed anhydride formed may if desired be extracted from the reaction mixture by evaporation of the solvent but it is not usually necessary to isolate this substance.  The second stage of the reaction is preferably carried out in the presence of a further mole of the amine or in the presence of an alkali metal carbonate in order to neutralise the acid formed.  A particularly suitable acid chloride (XCl) for use in the first stage of the process is benzoyl chloride. Several examples are given and the products have insecticidal properties.  The neutral salts of the O,O-dialkyl dithiophosphoryl fatty acids used as starting materials may be obtained by reacting a salt of an O,O-dialkyl-dithiophosphoric acid of the general formula (R1O)(R2O)P(S)SM wherein R1 and R2 are as defined above and M is a salt forming cation, e.g. Na, K or triethylammonium, with an a -halogeno-fatty acid of the formula Hal-CH(R3)COOH, suitably at from 10 DEG  to 100 DEG C. in an inert organic solvent, and neutralising the free fatty acid formed.  Specification 791,824 is referred to.ALSO:An insecticidal composition contains as active ingredient an O,O-dialkyl dithiophosphoryl fatty acid amide having the formula <FORM:0932011/VI/1> wherein R1 and R2 which may be the same or different are straight or branched chain alkyl groups containing from 1 to 4 carbon atoms, R3 is hydrogen a straight or branched chain alkyl group containing from 1 to 3 carbon atoms or a phenyl radical which may be unsubstituted or may bear one or more halogen substituents and/or C1-C3 alkyl groups and/or nitro groups and R4 and R5 which may be the same or different are hydrogen or alkyl, cycloalkyl, hydroxyalkyl, hydroxychloroalkyl or aryl groups said aryl groups being either unsubstituted or being substituted by one or more halogen atoms and/or C1-C3 alkyl groups and/or nitro groups or R4 and R5 taken together with the N atom to which they are attached form a heterocyclic ring, e.g. ethyleneimino, piperazino, pyrrolidino, piperidino or morpholino (see Group IV (b)).  Specification 791,824 is referred to.